Microscopes practical

• What is a stage?

  • its in the centre of the microscope
  • place of the microscope slide
  • has clips to hold the slide in place
• Where is the lamp and what does it do ?

  under the stage and the light from the lamp passes through the slide
• Where are the objective lenses and what do they do ?

  its above the stage and have the magnification of ,4x ,10,x or 40x
• Where is the eye piece and what is it for ?

  at the top of the microscope and you look through it and has the a magnification of 10x
• Steps to use an optical microscope on a prepared slide:

  1. Place the slide on the stage.

  2. Use the clips to hold it in place.

  3. Select the lowest power objective lens, usually 4x.

  4. Position the objective lens so it almost touches the slide, slowly turning the coarse focusing dial until it stops.

  5. When adjusting the objective lens, look at the microscope from the side.

  6. Look through the eyepiece and slowly turn the coarse focusing dial to increase the distance between the slide and the lens until the cells come into focus.

  7. Use the fine focusing dial to bring the cell into clear focus.
• How to calculate the total magnification ?

  magnification x eyepiece lens x objective lens

  e.g. 10 x 4 =40x